Noise normalization - Revision history

185.94.193.182 at 10:54, 23 November 2017

2017-11-23T10:54:20Z

← Older revision		Revision as of 10:54, 23 November 2017
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	'''Noise normalization''' is special type of coding technique (somewhat comparable [[PNS]] used in [[AAC]], but not the same) used by [[Ogg Vorbis]] psychoacoustics model to '''compensate''' for loss of energy in certain frequency bands due to quantization (usually because of a low [[SNR]]). The algorithm uses an apsort function to determine where the energy lost in each frequency band is the greatest and compensates the band with the greatest energy lost by '''reviving the residue''' (noise error) ''(see [https://trac.xiph.org/browser/trunk/vorbis/lib/psy.c psy.c] in source, '''_vp_noise_normalize_sort''' function, line 1050)''. This is main cause of most ''metallic artifacts'' in MP3. It is '''one factor''' that gives Vorbis ~~it's~~ '''noise-like''' sound characteristics, when the bitrate is too low to encode without susceptible artifacts. In the reference encoder it's used on all quality values less than 4.		'''Noise normalization''' is a special type of coding technique (somewhat comparable to [[PNS]] used in [[AAC]], but not the same) used by [[Ogg Vorbis]] psychoacoustics model to '''compensate''' for loss of energy in certain frequency bands due to quantization (usually because of a low [[SNR]]). The algorithm uses an apsort function to determine where the energy lost in each frequency band is the greatest and compensates the band with the greatest energy lost by '''reviving the residue''' (noise error) ''(see [https://trac.xiph.org/browser/trunk/vorbis/lib/psy.c psy.c] in source, '''_vp_noise_normalize_sort''' function, line 1050)''. This is main cause of most ''metallic artifacts'' in MP3. It is '''one factor''' that gives Vorbis its '''noise-like''' sound characteristics, when the bitrate is too low to encode without susceptible artifacts. In the reference encoder it's used on all quality values less than 4.

	==References==		==References==

Arite: Updated psy.c Trac link

2009-05-02T00:04:24Z

Updated psy.c Trac link

← Older revision		Revision as of 00:04, 2 May 2009
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	'''Noise normalization''' is special type of coding technique (somewhat comparable [[PNS]] used in [[AAC]], but not the same) used by [[Ogg Vorbis]] psychoacoustics model to '''compensate''' for loss of energy in certain frequency bands due to quantization (usually because of a low [[SNR]]). The algorithm uses an apsort function to determine where the energy lost in each frequency band is the greatest and compensates the band with the greatest energy lost by '''reviving the residue''' (noise error) ''(see [~~http~~://trac.xiph.org/~~cgi-bin/trac.cgi/file~~/trunk/vorbis/lib/psy.c psy.c] in source, '''_vp_noise_normalize_sort''' function, line 1050)''. This is main cause of most ''metallic artifacts'' in MP3. It is '''one factor''' that gives Vorbis it's '''noise-like''' sound characteristics, when the bitrate is too low to encode without susceptible artifacts. In the reference encoder it's used on all quality values less than 4.		'''Noise normalization''' is special type of coding technique (somewhat comparable [[PNS]] used in [[AAC]], but not the same) used by [[Ogg Vorbis]] psychoacoustics model to '''compensate''' for loss of energy in certain frequency bands due to quantization (usually because of a low [[SNR]]). The algorithm uses an apsort function to determine where the energy lost in each frequency band is the greatest and compensates the band with the greatest energy lost by '''reviving the residue''' (noise error) ''(see [https://trac.xiph.org/browser/trunk/vorbis/lib/psy.c psy.c] in source, '''_vp_noise_normalize_sort''' function, line 1050)''. This is main cause of most ''metallic artifacts'' in MP3. It is '''one factor''' that gives Vorbis it's '''noise-like''' sound characteristics, when the bitrate is too low to encode without susceptible artifacts. In the reference encoder it's used on all quality values less than 4.

	==References==		==References==

HotshotGG at 19:23, 4 November 2006

2006-11-04T19:23:08Z

← Older revision		Revision as of 19:23, 4 November 2006
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	'''Noise normalization''' is special type of coding technique (somewhat comparable [[PNS]] used in [[AAC]], but not the same) used by [[Ogg Vorbis]] psychoacoustics model to '''compensate''' for loss of energy in certain frequency bands due to quantization (usually because of a low [[SNR]]). The algorithm uses an apsort function to determine where the energy lost in each frequency band is the greatest and compensates the band with the greatest energy lost by '''reviving the residue''' ''(see [http://trac.xiph.org/cgi-bin/trac.cgi/file/trunk/vorbis/lib/psy.c psy.c] in source, '''_vp_noise_normalize_sort''' function, line 1050)''. This is main cause of most ''metallic artifacts'' in MP3. It is '''one factor''' that gives Vorbis it's ''noise-like'' sound characteristics, when the bitrate is too low to encode without susceptible artifacts. In the reference encoder it's used on all quality values less than 4.		'''Noise normalization''' is special type of coding technique (somewhat comparable [[PNS]] used in [[AAC]], but not the same) used by [[Ogg Vorbis]] psychoacoustics model to '''compensate''' for loss of energy in certain frequency bands due to quantization (usually because of a low [[SNR]]). The algorithm uses an apsort function to determine where the energy lost in each frequency band is the greatest and compensates the band with the greatest energy lost by '''reviving the residue''' (noise error) ''(see [http://trac.xiph.org/cgi-bin/trac.cgi/file/trunk/vorbis/lib/psy.c psy.c] in source, '''_vp_noise_normalize_sort''' function, line 1050)''. This is main cause of most ''metallic artifacts'' in MP3. It is '''one factor''' that gives Vorbis it's '''noise-like''' sound characteristics, when the bitrate is too low to encode without susceptible artifacts. In the reference encoder it's used on all quality values less than 4.

	==References==		==References==

HotshotGG at 20:36, 11 September 2006

2006-09-11T20:36:45Z

← Older revision		Revision as of 20:36, 11 September 2006
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	* [http://www.hydrogenaudio.org/forums/index.php?showtopic=20132 Noise Normalization and 'HF boost' problem] - The solution that ultimately lead to AoTuV tunings.		* [http://www.hydrogenaudio.org/forums/index.php?showtopic=20132 Noise Normalization and 'HF boost' problem] - The solution that ultimately lead to AoTuV tunings.


	~~[[Category:Technical]]~~
	[[Category:Algorithms]]		[[Category:Algorithms]]

HotshotGG at 20:10, 7 September 2006

2006-09-07T20:10:40Z

← Older revision		Revision as of 20:10, 7 September 2006
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	[[Category:Technical]]		[[Category:Technical]]
	[[Category:~~Algorithm~~]]		[[Category:Algorithms]]

HotshotGG at 20:10, 7 September 2006

2006-09-07T20:10:15Z

← Older revision		Revision as of 20:10, 7 September 2006
Line 6:		Line 6:

	[[Category:Technical]]		[[Category:Technical]]
	[[Category:~~Digital Signal Processing~~]]		[[Category:Algorithm]]

HotshotGG: You really can't expand this anymore in terms of explaining it in plain English

2006-09-07T00:38:26Z

You really can't expand this anymore in terms of explaining it in plain English

← Older revision		Revision as of 00:38, 7 September 2006
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	~~{{stub}}~~


	'''Noise normalization''' is special type of coding technique (somewhat comparable [[PNS]] used in [[AAC]], but not the same) used by [[Ogg Vorbis]] psychoacoustics model to '''compensate''' for loss of energy in certain frequency bands due to quantization (usually because of a low [[SNR]]). The algorithm uses an apsort function to determine where the energy lost in each frequency band is the greatest and compensates the band with the greatest energy lost by '''reviving the residue''' ''(see [http://trac.xiph.org/cgi-bin/trac.cgi/file/trunk/vorbis/lib/psy.c psy.c] in source, '''_vp_noise_normalize_sort''' function, line 1050)''. This is main cause of most ''metallic artifacts'' in MP3. It is '''one factor''' that gives Vorbis it's ''noise-like'' sound characteristics, when the bitrate is too low to encode without susceptible artifacts. In the reference encoder it's used on all quality values less than 4.		'''Noise normalization''' is special type of coding technique (somewhat comparable [[PNS]] used in [[AAC]], but not the same) used by [[Ogg Vorbis]] psychoacoustics model to '''compensate''' for loss of energy in certain frequency bands due to quantization (usually because of a low [[SNR]]). The algorithm uses an apsort function to determine where the energy lost in each frequency band is the greatest and compensates the band with the greatest energy lost by '''reviving the residue''' ''(see [http://trac.xiph.org/cgi-bin/trac.cgi/file/trunk/vorbis/lib/psy.c psy.c] in source, '''_vp_noise_normalize_sort''' function, line 1050)''. This is main cause of most ''metallic artifacts'' in MP3. It is '''one factor''' that gives Vorbis it's ''noise-like'' sound characteristics, when the bitrate is too low to encode without susceptible artifacts. In the reference encoder it's used on all quality values less than 4.

Beto at 21:06, 6 September 2006

2006-09-06T21:06:20Z

← Older revision		Revision as of 21:06, 6 September 2006
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	[[Category:Technical]]		[[Category:Technical]]
	[[Category:~~Algorithms~~]]		[[Category:Digital Signal Processing]]

Beto at 19:30, 5 September 2006

2006-09-05T19:30:24Z

← Older revision		Revision as of 19:30, 5 September 2006
Line 9:		Line 9:

	[[Category:Technical]]		[[Category:Technical]]
			[[Category:Algorithms]]

Beto at 19:29, 5 September 2006

2006-09-05T19:29:03Z

← Older revision		Revision as of 19:29, 5 September 2006
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	{{stub}}		{{stub}}


	'''Noise normalization''' is special type of coding technique (somewhat comparable [[PNS]] used in [[AAC]], but not the same) used by [[Ogg Vorbis]] psychoacoustics model to '''compensate''' for loss of energy in certain frequency bands due to quantization (usually because of a low [[SNR]]). The algorithm uses an apsort function to determine where the energy lost in each frequency band is the greatest and compensates the band with the greatest energy lost by '''reviving the residue''' ''(see [http://trac.xiph.org/cgi-bin/trac.cgi/file/trunk/vorbis/lib/psy.c psy.c] in source, '''_vp_noise_normalize_sort''' function, line 1050)''. This is main cause of most ''metallic artifacts'' in MP3. It is '''one factor''' that gives Vorbis it's ''noise-like'' sound characteristics, when the bitrate is too low to encode without susceptible artifacts. In the reference encoder it's used on all quality values less than 4.		'''Noise normalization''' is special type of coding technique (somewhat comparable [[PNS]] used in [[AAC]], but not the same) used by [[Ogg Vorbis]] psychoacoustics model to '''compensate''' for loss of energy in certain frequency bands due to quantization (usually because of a low [[SNR]]). The algorithm uses an apsort function to determine where the energy lost in each frequency band is the greatest and compensates the band with the greatest energy lost by '''reviving the residue''' ''(see [http://trac.xiph.org/cgi-bin/trac.cgi/file/trunk/vorbis/lib/psy.c psy.c] in source, '''_vp_noise_normalize_sort''' function, line 1050)''. This is main cause of most ''metallic artifacts'' in MP3. It is '''one factor''' that gives Vorbis it's ''noise-like'' sound characteristics, when the bitrate is too low to encode without susceptible artifacts. In the reference encoder it's used on all quality values less than 4.